We have winds here from 10-20 kts.
First I want one kite, but already decided that I don't want a 2-line kite, because it is quite gusty here.
I live in New Jersey and want to go in the ocean. Quiet cold already, but the next vacations are already planned.
My weight is 160 lbs and I want a twintip for the beginning. I have read that it is a lot easier for turns.
Which kite size would you suggest?

well, if you want a twin tip board, i would suggest a board like the wipika 186cm or a similar board.
the specifications of a beginner twintip are:
good upwind performance and it should start to glide early.

i recommend yuo buy a two line tube kite like the naish r3 or the wipika free air. these kites can easily be converted to four lines (tecnically, they ARE 4 line-kites with a bridle attached that makes ist possible to use two lines) a four line kite not only offers the possibility to depower, but turns much faster and needs an expierienced kiter to control it.
i can tell you that in the beginning you won't be able to use the depower-function because you won't be hooked up to the harness when starting to ride.
a kite like the r3 or free air has a better handling than the air blast or arx and it can be relaunched easily when dropped into the water.
when there are 10-20knots, i'd suggest to buy a 11m naish or a 8.9m free air.
you will be able to use these kites later in stonger winds when you are good and they still provide enough performance then.

but:

if you have no expierience with traction/power-kites, it is a MUST to take a course. this can be combined whith a nice holiday. kitesurfing is as dangerous as you make it. if you decide to learn it by try & error you risk serious injury or even worse, your life!
you may also risk to injure third persons!

there is no safe 'stop' mode like dropping the rigg on a windsurf-board.

Ok, sounds good.
That's what I thought too. Around 11 sqm.
Maybe you are right that I should wait until my holidays and take a course there.
It is only a few weeks to go and the water here is cold anyway. I'm sure that I will know better what to buy, when I did the course.
I'll let you guys know, how it went!

Do you know were you are taking the course yet? or when, like the month? I have tryed looking for places to go in New Jersey also. I found a place at http://www.realkiteboarding.com . Do you know this place or know if it is good or not?

Hi Shawn,
Since November many things have changed therefore I moved to Cali. I'll have my first lessons end of February. I don't know the places in NJ. But I'm sure there are/will be many of it.
Wishing you fun, Terence